diff --git a/src/media-understanding/apply.test.ts b/src/media-understanding/apply.test.ts
index e06adbc24..bc07de602 100644
--- a/src/media-understanding/apply.test.ts
+++ b/src/media-understanding/apply.test.ts
@@ -551,9 +551,8 @@ describe("applyMediaUnderstanding", () => {
     const { applyMediaUnderstanding } = await loadApply();
     const dir = await fs.mkdtemp(path.join(os.tmpdir(), "moltbot-media-"));
     // Create file with XML special characters in the name (what filesystem allows)
-    // Note: The sanitizeFilename in store.ts would strip most dangerous chars,
-    // but we test that even if some slip through, they get escaped in output
-    const filePath = path.join(dir, "file<test>.txt");
+    // We use '&' because it's valid on all platforms (including Windows) but still requires XML escaping
+    const filePath = path.join(dir, "file&test.txt");
     await fs.writeFile(filePath, "safe content");
 
     const ctx: MsgContext = {
@@ -575,10 +574,10 @@ describe("applyMediaUnderstanding", () => {
 
     expect(result.appliedFile).toBe(true);
     // Verify XML special chars are escaped in the output
-    expect(ctx.Body).toContain("&lt;");
-    expect(ctx.Body).toContain("&gt;");
-    // The raw < and > should not appear unescaped in the name attribute
-    expect(ctx.Body).not.toMatch(/name="[^"]*<[^"]*"/);
+    expect(ctx.Body).toContain("&amp;");
+    // The raw & should not appear unescaped in the name attribute
+    expect(ctx.Body).toContain('name="file&amp;test.txt"');
+    expect(ctx.Body).not.toContain('name="file&test.txt"');
   });
 
   it("normalizes MIME types to prevent attribute injection", async () => {